Reusable ultrasonic transducer and generator assemblies, surgical instruments including the same, and methods of manufacturing the same

ABSTRACT

An ultrasonic transducer and generator (TAG) assembly of a surgical instrument includes generator components and transducer components. The generator components are disposed within a first cavity cooperatively defined by a body portion and a cover. The generator components are covered in a thermally insulative material. The transducer components are disposed within a second cavity cooperatively defined by a proximal housing and a spinner housing.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 16/577,060 filed on Sep. 20, 2019, which claims thebenefit of and priority to U.S. Provisional Patent Application62/740,647, filed on Oct. 3, 2018, the entire contents of each of whichbeing incorporated by reference herein.

BACKGROUND Technical Field

The present disclosure relates to surgical instruments and, moreparticularly, to a reusable ultrasonic transducer and generator assemblyof an ultrasonic surgical instrument, an ultrasonic surgical instrumentincorporating the same, and methods of manufacturing the same.

Background of Related Art

Some surgical instruments have an end effector configured to applyenergy to tissue to treat tissue. An example of such a surgicalinstrument is an ultrasonic surgical instrument that utilizes ultrasonicenergy, i.e., ultrasonic vibrations, to treat tissue. More specifically,a typical ultrasonic surgical instrument utilizes mechanical vibrationenergy transmitted at ultrasonic frequencies to coagulate, cauterize,fuse, seal, cut, desiccate, fulgurate, or otherwise treat tissue. Suchan ultrasonic surgical instrument is configured to transmit ultrasonicenergy produced by, for example, a generator and transducer assembly,along a waveguide to an end effector that is spaced-apart from thegenerator and transducer assembly. The end effector may include a bladeand a jaw member configured to clamp tissue against the blade to treattissue.

Typically, after a use of the ultrasonic surgical instrument, thegenerator and transducer assembly is sterilized and reused. However,sterilization processes may involve high pressure, extreme heat, and/ormoisture that may damage internal components of the generator andtransducer assembly.

Accordingly, a need exists for a generator and transducer assembly thatcan better withstand multiple cycles of various sterilization processes,a surgical instrument including the same, and a method of manufacturingthe same.

SUMMARY

In one aspect of the present disclosure, a surgical instrument includesa handle assembly, an elongated body portion extending distally from thehandle assembly, a blade extending distally from the elongated bodyportion, and an ultrasonic transducer and generator (“TAG”) assembly forconnection to the handle assembly. The TAG assembly is configured toenergize the blade member when connected to the handle assembly andincludes generator components and transducer components. The generatorcomponents are disposed within a first cavity cooperatively defined by abody portion and a cover. A portion of the generator components iscovered in a thermally insulative material. The transducer componentsare disposed within a second cavity cooperatively defined by a proximalhousing and a spinner housing. The proximal housing is coupled to thebody portion.

In aspects, the thermally insulative material may be a custom conformalcoating.

In aspects, the thermally insulative material may be fabricated from agel or an epoxy.

In aspects, the thermally insulative material may be a silicone gel thatcovers a top surface of a printed circuit board of the generatorcomponents and a bottom surface of the printed circuit board.

In aspects, the thermally insulative material may fill the first cavity.

In aspects, the cover may be ultrasonically welded to an upper portionof the body portion to hermetically seal the generator components in thefirst cavity.

In aspects, the proximal housing may be ultrasonically welded to thespinner housing to hermetically seal the transducer components withinthe second cavity.

In aspects, each of the body portion, the cover, the proximal housing,and the spinner housing may be fabricated from a high temperatureresistant plastic.

In aspects, the transducer components include a pair of washers, apiezoelectric stack disposed between the pair of washers, and a hornextending distally from the piezoelectric stack. The pair of washers maybe fabricated from a material having a similar coefficient of thermalexpansion as the piezoelectric stack.

In aspects, the generator components may include an electrical pinconnector pre-molded to a pin block and insert-molded into an upperportion of the body portion. A high temperature and moisture resistantsealant may be coated on an interface between the electrical pinconnector and the pin block.

In another aspect of the present disclosure, a method of manufacturing aTAG assembly is provided and includes covering a portion of generatorcomponents in a thermally insulative material, hermetically sealing thegenerator components in a first cavity cooperatively defined by a bodyportion and a cover, and hermetically sealing transducer componentswithin a second cavity cooperatively defined by a proximal housing and aspinner housing.

In some methods, covering the portion of the generator components mayinclude applying a custom conformal coating on the portion of thegenerator components.

In some methods, covering the portion of the generator components mayinclude filling the first cavity with the thermally insulative materialvia a hole formed in the cover and sealing the hole in the cover.

In some methods, the cover may be ultrasonically welded to an upperportion of the body portion to hermetically seal the generatorcomponents in the first cavity.

Some methods may further include pre-molding an electrical pin connectorto a pin block, insert-molding the electrical pin connector into anupper portion of the body portion, and coating the electrical pinconnector with a high temperature and moisture resistant sealant.

In yet another aspect of the present disclosure, an ultrasonictransducer and generator (TAG) assembly of an ultrasonic surgicalinstrument is provided. The TAG assembly includes a body portion, acover configured to couple to the body portion, and generator componentsdisposed within a first cavity cooperatively defined by the body portionand the cover when the body portion and the cover are coupled to oneanother. A portion of the generator components is covered in a thermallyinsulative material. The TAG assembly further includes a proximalhousing, a spinner housing configured to couple to the proximal housing,and transducer components disposed within a second cavity cooperativelydefined by the proximal housing and the spinner housing when theproximal housing and the spinner housing are coupled to one another. Thetransducer components include a pair of washers, a piezoelectric stackdisposed between the pair of washers, and a horn extending distally fromthe piezoelectric stack. The pair of washers are fabricated from amaterial having a similar coefficient of thermal expansion as thepiezoelectric stack

Further details and aspects of exemplary aspects and features of thepresent disclosure are described in more detail below with reference tothe appended figures.

As used herein, the terms parallel and perpendicular are understood toinclude relative configurations that are substantially parallel andsubstantially perpendicular up to about + or −10 degrees from trueparallel and true perpendicular.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects and features of the present disclosure willbecome more apparent in view of the following detailed description whentaken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a perspective view of an illustrative embodiment of anultrasonic surgical instrument provided in accordance with the presentdisclosure, including a TAG assembly thereof disconnected from a handleassembly;

FIG. 2 is an exploded, perspective view of a shaft, a waveguide, and atool assembly of the ultrasonic surgical instrument of FIG. 1;

FIG. 3 is a perspective view of the TAG assembly of FIG. 1;

FIG. 4 is a perspective view, with parts separated, of the TAG assemblyof FIG. 3;

FIG. 5 is a perspective view, with parts separated, of generatorcomponents of the TAG assembly and a body portion of the TAG assembly ofFIG. 1;

FIG. 6 is a perspective view, with parts separated, of the generatorcomponents of FIG. 5 and an inner housing;

FIG. 7 is a side view, with parts removed or shown transparent, of theTAG assembly of FIG. 1, illustrating the generator and transducercomponents of the TAG assembly;

FIG. 8 is a perspective view, with parts separated, of the transducerassembly disconnected from the body portion of the TAG assembly of FIG.1; and

FIG. 9 is a perspective view, with parts separated, of the transducercomponents of the transducer assembly of FIG. 8.

DETAILED DESCRIPTION

Embodiments of the presently disclosed ultrasonic surgical instrumentsincluding transducer and generator (“TAG”) assemblies, and methods ofmanufacturing thereof, are described in detail with reference to thedrawings, in which like reference numerals designate identical orcorresponding elements in each of the several views. As used herein theterm “distal” refers to that portion of the surgical instrument and/orTAG assembly thereof that is closer to the patient, while the term“proximal” refers to that portion of the surgical instrument and/or TAGassembly that is farther from the patient.

The present disclosure is directed to a water-proof, auto-washable andautoclave compatible TAG assembly manufactured to withstand repeatedsterilization cycles without being damaged. The generator and transducercomponents of the TAG assembly are both hermetically sealed within arespective housing, and are coated with thermally insulative material,such as, for example, a silicone gel. A piezoelectric stack of thetransducer assembly is surrounded by materials having a similar or thesame coefficient of thermal expansion as the piezoelectric stack toprevent cracking of the piezoelectric stack.

With reference to FIGS. 1 and 2, an ultrasonic surgical instrument 10 isillustrated and generally includes a handle assembly 12, an elongatedbody portion 14, and a tool assembly 16. Tool assembly 16 includes ablade 13 and a clamp member or jaw member 15. Handle assembly 12supports a battery assembly 18 and an ultrasonic transducer andgenerator assembly (“TAG”) 20, and includes a rotatable nozzle 22, anactivation button 24, and a clamp trigger 26. Handle assembly 12includes a body portion 28 defining a recess 32 in a proximal portionthereof dimensioned for releasable receipt of TAG 20 therein. Batteryassembly 18 is connected to a lower end of handle assembly 12 to definea fixed handgrip portion of handle assembly 12. Suitable configurations,both cordless and tethered, for providing power and ultrasonic energy,are also contemplated.

Battery assembly 18 and TAG 20 are each releasably secured to handleassembly 12 to facilitate disposal of the entire device, with theexception of battery assembly 18 and TAG 20. However, it is contemplatedthat any or all of the components of ultrasonic surgical instrument 10may be configured as disposable single-use components or sterilizablemulti-use components. TAG 20 includes a generator assembly 100 and anultrasonic transducer assembly 200. TAG 20 and its components will bedescribed in further detail below with reference to FIGS. 3-9.

Elongated body portion 14 of ultrasonic surgical instrument 10 includesa waveguide 30, which extends distally from handle assembly 12 to toolassembly 16. A distal portion of the waveguide 30 defines blade 13 oftool assembly 16. A proximal portion of the waveguide 30 is configuredto engage TAG 20. Elongated body portion 14 of ultrasonic surgicalinstrument 10 further includes an isolation tube 36 positioned aboutwaveguide 30 to prevent the transfer of ultrasonic energy from waveguide30 to an inner support tube 42 of elongated body portion 14. Thewaveguide 30 and the inner support tube 42 are rotatably coupled torotatable nozzle 22 such that rotation of nozzle 22 effectscorresponding rotation of the inner support tube 42 and the waveguide30. Elongated body portion 14 further includes an actuator tube 66coupled to inner support tube 42 and configured to rotate upon rotationof nozzle 22.

Inner support tube 42 of elongated body portion 14 is positioned aboutisolation tube 36 and includes a distal end having a pair of spacedclamp support arms 52. Spaced clamp support arms 52 are configured topivotally engage jaw member 15 of tool assembly 16 to enable pivoting ofjaw member 15 between an open position, in which jaw member 15 is spacedfrom blade 13, and a closed position, in which jaw member 15 isapproximated relative to blade 13. Jaw member 15 is moved between theopen and closed positions in response to actuation of clamp trigger 26.

Outer actuator tube 66 of elongated body portion 14 is slidablysupported about inner support tube 42 (although actuator tube 66 mayalternatively be slidably disposed within support tube 42) and isoperably coupled to jaw member 15 such that jaw member 15 is pivotedfrom the open position to the closed position as actuator tube 66 isslid about inner support tube 42. Actuator tube 66 is operably coupledwith rotatable nozzle 22 such that outer actuator tube 66 is rotatablysecured to, and slidable relative to, rotatable nozzle 22. Further, aproximal portion of outer actuator tube 66 is operably coupled with adrive mechanism 80 of handle assembly 12.

Handle assembly 12 includes drive mechanism 80 supported therein forlinear movement relative to handle assembly 12. Handle assembly 12 alsoincludes the aforementioned clamp trigger 26, which is operably coupledwith drive mechanism 80 such that, in use, when clamping trigger 26 iscompressed towards battery assembly 18, outer actuator tube 66 is slidabout support tube 42 (in a distal-to-proximal or proximal-to-distaldirection) to pivot jaw member 15 from the open position to the closedposition in relation to blade 13.

In general, in use, when battery assembly 18 and TAG 20 are attached tohandle assembly 12 and waveguide 30, respectively, and ultrasonicsurgical instrument 10 is activated, e.g., via actuation of activationbutton 24, battery assembly 18 provides power to generator assembly 100of TAG 20, which, in turn, generates an AC signal to drive theultrasonic transducer assembly 200 of TAG 20. The ultrasonic transducerassembly 200, in turn, converts the AC signal into high frequencymechanical motion. This high frequency mechanical motion produced by theultrasonic transducer assembly 200 is transmitted to blade 13 viawaveguide 30 for application of such ultrasonic energy to tissueadjacent to or clamped between blade 13 and jaw member 15 of toolassembly 16 to treat the tissue.

With reference to FIGS. 3-9, TAG 20 is described. TAG 20 is configuredto be received in the recess 32 (FIG. 1) of the handle assembly 12 andgenerally includes the generator assembly 100, the transducer assembly200, and a body portion 102 supporting both the generator and transducerassemblies 100, 200. The body portion 102 includes an upper portion 102a supporting generator components 104 of the generator assembly 100. Thebody portion 102 also has a proximal support member 106 and a distalsupport member 108 each of which extends beneath the upper portion 102 ato define a cradle that rotatably supports the transducer assembly 200.

With reference to FIGS. 5 and 6, the upper portion 102 a of the bodyportion 102 defines a recess 110 therein configured for receipt of thegenerator components 104 of the generator assembly 100. The generatorcomponents 104 include an electrical pin connector 112 and a printedcircuit board assembly (“PCBA”) 114 each deposited within the recess 110of the body portion 102. The electrical pin connector 112 may be a14-pin electrical connector, wherein each of the pins may be right-anglepins that are insert-molded into a bottom portion or floor 102 b of thebody portion 102. However, other suitable electrical connectors, circuitboards, and/or other components are also contemplated.

The body portion 102 has a distal end defining a port 116 through whicha first portion 118 a of the electrical pin connector 112 extend. Thefirst portion 118 a is configured for receipt in electrical contacts(not explicitly shown) supported on the body portion 28 of the handleassembly 12 to electrically connect the TAG 20 and the smart batteryassembly 18 via a connector, e.g., a flex circuit, extending throughbody portion 28 (see FIG. 1). Once connected, an actuation of theactuation button 24 of the handle assembly 12 will affect a delivery ofpower from the battery assembly 18 to the generator assembly 100 via theelectrical pin connector 112 (see also FIG. 1). A second portion 118 bof the electrical pin connector 112 extends upwardly through respectiveopenings defined in the PCBA 114 and a pin block 120 that is disposedtoward a distal end of the recess 110 of the body portion 102.

With reference to FIGS. 5-7, the PCBA 114 of the generator assembly 100has an upper surface 114 a and a lower surface 114 b each covered withthe conformal coating 122. The coating 122 is a thermally insulativematerial, such as, for example, a suitable epoxy or gel, having athickness from about 0.5 mm to about 8 mm. In embodiments, the thermallyinsulative material may have a thickness from about 2 mm to about 6 mm.In embodiments, the thermally insulative material may be a silicone gel.The thermally insulative material protects all joints and components ofthe PCBA 114, and any adjacent components, from the stress of thermaland moisture cycling.

The generator assembly 100 further includes an inner housing 124 and anouter housing or cover 126. The inner housing 124, the outer cover 126,and the body portion 102 may each be fabricated from a high temperatureresistant plastic including, but not limited to, polyphenylsulfone,polyaryletherketone, polyether ether ketone, polyetherimide, aliquid-crystal polymer, or any suitable combination thereof. The innerhousing 124 couples to lateral portions of the PCBA 114 (e.g., viafasteners 128 or a snap-fit engagement) and partially covers the PCBA114 and the second portion 118 b of the electrical pin connector 112.

The outer cover 126 of the generator assembly 100 has a lower rim 130configured to be received in a track 132 defined along the outerperiphery of the upper portion 102 a of the body portion 102. The outercover 126 and the upper portion 102 a of the body portion 102, whencoupled, cooperatively define a cavity 134 for receipt of the innerhousing 124, the PCBA 114, and the second portion 118 b the electricalpin connector 112. As such, upon coupling the outer cover 126 to theupper portion 102 a of the body portion 102, the outer cover 126 and theupper portion 102 a of the body portion 102 cooperate to encapsulate theinner housing 124, the PCBA 114, and the second portion 118 b of theelectrical pin connector 112. The lower rim 130 of the outer cover 126may be coupled to the track 132 of the body portion 102 via ultrasonicwelding to hermetically seal the generator components 104 within thecavity 134. In embodiments, the outer cover 126 may be coupled to thebody portion 102 via any suitable fastening engagement, whether beingpermanent or detachable.

During manufacture of the generator assembly 100 of the TAG 20, theelectrical pin connector 112 is pre-molded to the pin block 120 and thePCBA 114 using a polymer, such as for example, a liquid-crystal polymer.In embodiments, the electrical pin connector 112 may be pre-molded tothe pin block 120 and the PCBA 114 using any suitable adhesive. Theupper and lower surfaces 114 a, 114 b of the PCBA 114 are coated withthe thermally insulative material 122 using a conformal coating process,as detailed below. The pin block 120 is insert-molded into the recess110 of the body portion 102 and then a sealant, such as an epoxysealant, is sued to seal the molding interface for hermeticity. Afterapplying the conformal coating of the thermally insulative material 122to the PCBA 114, the now-insulated PCBA 114 and the electrical pinconnector 112 are insert-molded into the recess 110 of the body portion102. A high temperature and moisture resistant sealant, such as, forexample, an epoxy, is coated on each of the pins of the electrical pinconnector 112 to seal the apertures in the floor 102 b of the bodyportion 102, in the PCBA 114, and in the pin block 120. The sealantprevents the opening of a leak path between the pins and the bodyportion 102.

With the generator components 104 disposed within the recess 110 of thebody portion 102, the outer cover 126 of the generator assembly 100 ispositioned over the generator components 104 and the lower rim 130 ofthe outer cover 126 is inserted into the track 132 of the body portion102. To fix the outer cover 126 to the body portion 102, an ultrasonicweld is applied to the lower rim 130 of the outer cover 126, therebyhermetically sealing the generator components 104 (e.g., the electricalpin connector 112 and the PCBA 114) in the cavity 134.

In an alternate embodiment, the thermally insulative material 122 may beapplied after insertion of the PCBA 114 into the body portion 102instead of or in addition to being applied prior. For example, aftercovering the PCBA 114 with the outer cover 126, the thermally insulativematerial 122 may be injected into the cavity 134 via a hole (not shown)formed in the outer cover 126. The thermally insulative material 122 maybe injected until the cavity 134 is substantially filled with thethermally insulative material 122. It is contemplated that the thermallyinsulative material 122 may fill the entire cavity 134 of the outercover 126. The hole in the outer cover 126 may then be filled using asealant (e.g., an epoxy).

With reference to FIGS. 3, 4 and 7-9, the transducer assembly 200 of TAG20 is described. The transducer assembly 200 extends through theproximal end of the body portion 102 and is rotatably supported on thecradle defined by supports 106, 108. The transducer assembly 200generally includes a proximal housing 202, a spinner housing 226, andtransducer components 204 configured to be received within a cavitycooperatively defined by the proximal housing 202 and the spinnerhousing 226 when the proximal housing 202 and the spinner housing 226are coupled to one another. The proximal housing 202 and the spinnerhousing 226 may be fabricated from a high temperature resistant plasticincluding, but not limited to, polyphenylsulfone, polyaryletherketone,polyether ether ketone, polyetherimide, a liquid-crystal polymer, or anysuitable combination thereof. The proximal housing 202 and the spinnerhousing 226 may be ultrasonically welded to one another to hermeticallyseal the transducer components 204 therein, as will be described ingreater detail below.

The proximal housing 202 has a torque knob 206 at its proximal end. Whenthe proximal housing 202 is supported on the body portion 102, thetorque knob 206 extends from the proximal end of the body portion 102.The torque knob 206 includes an internal surface with a plurality oflongitudinal ribs 208 defining longitudinal recesses 210 therebetween.The longitudinal recesses 210 receive corresponding tabs 212 extendingproximally from an internal housing 214 positioned about the transducercomponents 204, whereby rotation of the torque knob 206 causescorresponding rotation of the internal housing 214.

With reference to FIGS. 7-9, the proximal housing 202 and the spinnerhousing 226 support the transducer components 204 of the TAG 20,including a piezoelectric stack 216 and a forwardly extending horn 218.Horn 218 has a horn flange 220 secured thereto having a polygonalcross-section. The horn 218 has a threaded bore 222 at its distal endthat threadably engages a threaded extension 34 of the waveguide 30(FIG. 2). The internal housing 214 and the transducer components 204 arepositioned within a longitudinal bore 224 extending through the spinnerhousing 226. The longitudinal bore 224 of the spinner housing 226 has apolygonal cross-sectional configuration corresponding to the outercross-sectional configuration of the internal housing 214 and the hornflange 220, whereby rotation of the internal housing 214 causescorresponding rotation of the spinner housing 226 and the horn flange220.

The piezoelectric stack 216 of the transducer components 204 includesfirst and second electrodes 228 disposed between piezoelectric elementsof the piezoelectric stack 216. The electrodes 228 include correspondingfirst and second electrode extensions 232 extending distally from thepiezoelectric stack 216. The piezoelectric stack 216 may includetransducer crystals and electrodes 228 that are outer diameter centeredrather than inner diameter centered to simplify the assembly of thetransducer components 204. The outer diameter centering ensures aconcentric arrangement of the transducer crystals and the electrodes228. The electrodes 228 may have an outer diameter that is larger thanthe transducer crystals and an inner diameter that is smaller than thetransducer crystals to allow for tolerances and ease of assembly.Transducer assembly 200 includes first and second spaced-apart contactrings 230 a, 230 b disposed annularly about the exterior of the spinnerhousing 226. The first and second contact rings 230 a, 230 b arerotatably associated with corresponding contacts 140 of the generatorassembly 100 (FIG. 5) that extend through the floor 102 b of the bodyportion 102. A sealant (e.g., an epoxy) may be applied to the contactrings 230 a, 230 b to seal off the contact rings and the spinner housing226.

To drive the piezoelectric stack 216, the first and second electrodes228 are energized by first and second electrical potentials,respectively. In order to supply these first and second potentials tothe electrodes 228, the generator components 104 of the TAG 20 providethe first and second electrical potentials to the contacts 140 of thegenerator assembly 100, which transmit the first and second electricalpotentials to the first and second electrodes 228 of the piezoelectricstack 216 via the first and second contact rings 230 a, 230 b.

The transducer components 204 further include a proximal washer 234 anda distal washer 236 disposed on opposite ends of the piezoelectric stack216, respectively. The washers 234, 236 may be fabricated from a metal,wherein the proximal washer 234 may be fabricated from martensiticstainless steel and the distal washer 236 may be fabricated fromtitanium. It is contemplated that the washers 234, 236 may be fabricatedfrom any suitable material having a similar or the same coefficient ofthermal expansion as the piezoelectric stack 216. In embodiments, thehorn 218 may also have the same or similar coefficient of thermalexpansion as the piezoelectric stack 216. By having the same or similarcoefficient of thermal expansion as the piezoelectric stack 216, thewashers 234, 236 and horn 218 prevent cracks from forming in thepiezoelectric stack 216 during thermal cycling. The horn 218 may helpguide assembly to prevent scraping of PTFE liner. A stress rod 23 may befixed to a proximal end of the horn 218 and extend proximally therefrom.A proximal end of the stress rod 23 may be coupled to a nut 24 disposedproximally of the washer 234 or within the washer 234. The nut 24 may bea hexagonal nut and is tightened onto the stress rod 23 to fix thepiezoelectric stack 216 in place. The stress rod 23 may screw into thehorn 218 and then the nut 24 may be screwed onto the stress rod 23. Thestress rod 23 may experience tension during and after the nut 24 isscrewed into place.

The transducer components 204 further include a bushing 240 positionedproximally of the horn flange 220, and an O-ring 242 positioned distallyof the horn flange 220. The bushing 240 is positioned between a distalsurface of the internal housing 214 and a proximal face of the hornflange 220, and functions to support the transducer components 204 whileinhibiting the transfer of ultrasonic vibration to the spinner housing226. The O-ring 242 is positioned between a proximal surface of thespinner housing 226 and a distal face of the horn flange 220, and sealsthe horn flange 220 to the spinner housing 226 to further inhibit thetransfer of ultrasonic vibration to the spinner housing 226.

A bushing 246 (e.g., a TEFLON bushing) is received within a first groove284 formed in a proximal end of the spinner housing 226. The bushing 246is positioned distally of the distal support member 108 of the bodyportion 102 of the TAG 20 in order to inhibit binding of the transducercomponents 204 during rotation. Additionally, a spiral ring 248 isreceived within a second grove 250 formed in the proximal end of thespinner housing 226. The spiral ring 248 is positioned distally of thebushing 246 in order to retain the spinner housing 226 within the bodyportion 102 of the TAG 20.

During manufacture of the transducer assembly 200 of TAG 20, thepiezoelectric stack 216 is positioned within the proximal housing 202and the spinner housing 226. For example, a distal end of the proximalhousing 202 may be received in a proximal end of the spinner housing226, followed by welding of the distal end of the proximal housing 202to the proximal end of the spinner housing 226. The proximal housing 202and the spinner housing 226 are ultrasonically welded to one another tohermetically seal the piezoelectric stack 216 and the washers 234, 236therein. To attach the TAG 20 to the body portion 28 of the handleassembly 12, the transducer assembly 204 is positioned in the circularrecess portion 32 (FIG. 1) of the body portion 28 of the handle assembly12, during which time, the threaded extension 34 (FIG. 2) of thewaveguide 30 is received in the threaded bore 222 (FIG. 7) of the horn218. In order to threadably secure the waveguide 30 to the horn 218, therotatable nozzle 22 is gripped, and the horn 218 is rotated by rotatingthe proximal housing 202 via the torque knob 206.

After a use of the ultrasonic surgical instrument 10, the TAG 20 may bedetached from the handle assembly 12 and put through a sterilizationcycle. Due to above-described construction of the TAG 20, the generatorcomponents 104 and the transducer components 204 of the TAG 20 canundergo high heat, high pressure, and/or high moisture sterilizationprocesses without being damaged.

The performance of the piezoelectric stack 216 of the transducercomponents 204 may be impacted by going through a high temperatureprocess (i.e. an autoclave). As described in U.S. Pat. No. 9,943,326,the entire contents of which being incorporated by reference herein, theperformance of the transducer may be calibrated prior to its use andthen adjusted based on its usage. The calibration may also employ analgorithm that adjusts the calibration in expectation that thetransducer will be put through a high temperature autoclave cycle beforeit is used. The algorithm may include a reduction in the calibration ofthe transducer by about 1% to about 5% and, in some embodiments about2.2%, to counteract the effects of the autoclave.

In embodiments, the transducer may be equipped with a sensor configuredto sense the number of times the transducer underwent an autoclave. Thecalibration of the transducer may be changed based on the number ofautoclaves the transducer endured.

The acoustic wave velocity produced by the transducer was found toincrease by 15-20% over the first 25-50 autoclave cycles, whereby theperformance of the transducer substantially stabilizes after the first25-50 autoclave cycles. It was found that by baking the transducer atapproximately 150° C. for approximately 40 hours, the change in velocitywas reduced from about 15-20% to about 2%. Baking the transducer athigher temperatures risks degrading the performance of the transducers,whereas baking the transducer at lower temperatures requires more baketime to get the same effect. Accordingly, prior to use of thepiezoelectric stack 216, the piezoelectric stack 216 may be autoclavedat about 140° C. to about 160° C. for about 30 hours to about 50 hours.In this way, the impact of future autoclaves on the piezoelectric stack216 will be reduced.

While several embodiments of the disclosure have been shown in thedrawings, it is not intended that the disclosure be limited thereto, asit is intended that the disclosure be as broad in scope as the art willallow and that the specification be read likewise. Therefore, the abovedescription should not be construed as limiting, but merely asexemplifications of particular embodiments. Those skilled in the artwill envision other modifications within the scope and spirit of theclaims appended hereto.

What is claimed is:
 1. An ultrasonic transducer and generator (TAG)assembly configured to energize an ultrasonic blade, the TAG assemblycomprising: a generator assembly including: a body portion; a coverconfigured to attach to the body portion, the body portion and the covercooperatively defining a first cavity when the cover is attached to thebody portion; and at least one generator component configured forreceipt within the first cavity, wherein the at least one generatorcomponent is covered in a thermally insulative material; and atransducer assembly including: a proximal housing; a spinner housingconfigured to attach to the proximal housing, the proximal housing andthe spinner housing cooperatively defining a second cavity when thespinner housing is attached to the proximal housing; and at least onetransducer component configured for receipt within the second cavity. 2.The TAG assembly according to claim 1, wherein the proximal housing isconfigured to couple to the body portion.
 3. The TAG assembly accordingto claim 1, wherein the thermally insulative material is a conformalcoating.
 4. The TAG assembly according to claim 1, wherein the thermallyinsulative material is fabricated from at least one of a gel or anepoxy.
 5. The TAG assembly according to claim 4, wherein the at leastone generator component includes a printed circuit board, the thermallyinsulative material being a silicone gel that covers a top surface ofthe printed circuit board and a bottom surface of the printed circuitboard.
 6. The TAG assembly according to claim 1, wherein the thermallyinsulative material fills the first cavity.
 7. The TAG assemblyaccording to claim 1, wherein the cover is ultrasonically welded to anupper portion of the body portion to hermetically seal the at least onegenerator component within the first cavity.
 8. The TAG assemblyaccording to claim 1, wherein the proximal housing is ultrasonicallywelded to the spinner housing to hermetically seal the at least onetransducer component within the second cavity.
 9. The TAG assemblyaccording to claim 1, wherein each of the body portion, the cover, theproximal housing, and the spinner housing is fabricated from a hightemperature resistant plastic.
 10. The TAG assembly according to claim1, wherein the at least one transducer component includes: a pair ofwashers; a piezoelectric stack disposed between the pair of washers; anda horn extending distally from the piezoelectric stack.
 11. The TAGassembly according to claim 10, wherein the pair of washers arefabricated from a material having a similar coefficient of thermalexpansion as the piezoelectric stack.
 12. The TAG assembly according toclaim 1, wherein the at least one generator component includes anelectrical pin connector pre-molded to a pin block and insert-moldedinto an upper portion of the body portion.
 13. The TAG assemblyaccording to claim 12, wherein a high temperature and moisture resistantsealant is coated on an interface between the electrical pin connectorand the pin block.
 14. A method of manufacturing an ultrasonictransducer and generator (TAG) assembly, the method comprising: coveringat least one generator component of the TAG assembly within a thermallyinsulative material; hermetically sealing the at least one generatorcomponent in a first cavity defined by a generator housing assembly; andhermetically sealing at least one transducer component of the TAGassembly within a second cavity defined by a transducer housingassembly.
 15. The method according to claim 14, further comprisingcoupling the generator housing assembly and the transducer housingassembly to one another.
 16. The method according to claim 14, whereincovering the at least one generator component includes applying aconformal coating on the at least one generator component.
 17. Themethod according to claim 14, wherein covering the at least onegenerator component includes: filling the first cavity with thethermally insulative material via a hole formed in a cover of thegenerator housing assembly; and sealing the hole in the cover.
 18. Themethod according to claim 14, wherein a cover of the generator housingassembly is ultrasonically welded to an upper portion of a body portionof the generator housing assembly to hermetically seal the at least onegenerator component within the first cavity.
 19. The method according toclaim 14, further comprising: pre-molding an electrical pin connector toa pin block; insert-molding the electrical pin connector into thegenerator housing assembly; and coating the electrical pin connectorwith a high temperature and moisture resistant sealant.
 20. The methodaccording to claim 14, wherein the at least one transducer componentincludes: a pair of washers; a piezoelectric stack disposed between thepair of washers; and a horn extending distally from the piezoelectricstack, the pair of washers being fabricated from a material having asimilar coefficient of thermal expansion as the piezoelectric stack.